Antenna



FIG. 1 is a front perspective view of an antenna of our new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right-side view thereof, the left-side being a mirror image thereof; and,

FIG. 6 is a top plan view thereof. 

The ornamental design for an antenna, as shown and described. 